N-, P-, and Ni-Co-doped Porous Carbon from Poplar Powder and Graphene Oxide Composites as Electrode Materials for Supercapacitors

Poplar powder was used as a raw material to prepare an electrode material in supercapacitors by doping modification, carbonization, and activation. The lignin-removed poplar powder was mixed with graphene oxide, melamine, and diammonium hydrogen phosphate and then compounded with nickel sulfate. Upon carbonization and activation with KOH, the composite becomes a hierarchical porous carbon material with a pore volume of 0.93 cm3 g-1 and a surface area of 1214.1 m2 g-1. At 0.5 A g-1 current per square meter, the specific capacitance was 407.5 F g-1. In addition, 92.6% of the capacitance remained even after 3000 charging and discharging cycles. There was an outstanding power and energy density of 12.32 W h kg-1 at 499.99 W kg-1 for a symmetric supercapacitor in 6 M KOH. Co-doped porous carbon with nitrogen, phosphorous, and nickel could be a good electrode material for energy storage devices.

Automated summary

Poplar powder was used as raw material for electrode material in supercapacitors through doping modification, carbonization, and activation. The resulting hierarchical porous carbon material exhibited a pore volume of 0.93 cm3 g-1 and a surface area of 1214.1 m2 g-1. It showed a specific capacitance of 407.5 F g-1 at 0.5 A g-1 current density, and retained 92.6% of its capacitance after 3000 cycles. Additionally, a symmetric supercapacitor achieved an outstanding power and energy density of 12.32 W h kg-1 at 499.99 W kg-1 in 6 M KOH. Co-doped porous carbon with nitrogen, phosphorous, and nickel demonstrated potential as a good electrode material for energy storage devices.